Tactile cues and feedback enhance the human-machine interface. Providing tactile feedback increases the amount of information available to a user in the operation of a device. Some devices utilize structural tactile methods. One such example is to provide a raised surface on an input surface, e.g., keypad, of the device. Such methods, however, are inherently static, and thus, cannot offer a wide array of, or effective, tactile feedback. Whereas before, one had to rely solely on aural, visual, and/or structural tactile cues, haptics increasingly provide greater and more effective physical cues to users of various devices.
A device may incorporate a variety of technologies for providing haptic feedback, including active and/or passive devices. Active haptic feedback devices, including, for example, motors, add energy to a system. Passive haptic feedback devices (also referred to as resistive devices), such as brakes, remove energy from a system.
Resistive devices have a number of advantages over active devices, including, for example, reduced manufacturing cost and lower power consumption. A noteworthy shortcoming of resistive devices, however, is that resistive devices typically can only oppose a motion or movement. Thus, unlike active devices, resistive devices generally cannot provide assistive forces that may be useful in directing a user to a preferred location.